Retrievable well packer



. y 1 19 2. c. E. BURT 2,290,142

RETRIEVABLE WELL PACKER Filed Dec. 23, 1939 gamma tom CLARE/vee- .5: 30k? Patented July 14, 1942 'RETRAIEVABLE WELL PACKER Clarence E. Burt, Los Angeles, Calif., assignor to Baker Oil vTools,'Inc., Huntington Park, Calif., a corporation of California Application December 23, 1939, Serial No; 310,810

13 Claims. (Cl. 16612) The present invention relates to wellpackers, andpmore particularly to packers which are ca pable of being retrieved after having been set in the casing.

- It is an objectof the invention to provide an improved retrievable well packer capable of remaining in set position within a well casing without the necessity of imposing external loading upon it.

A-,fur ther object of the invention isto provide an hydraulically set well packer adapted to positively support downwardly directed loads only, in order to permit its retrieval from the well bore simply by subjecting it to upwardly directed pulling ,efiort.

This invention has 'otherobjects which will become-apparent from a consideration of oneform in which it is embodied, shown in the drawing accompanying and forming part of the present specification. ;This form willnow bedescribed in detail, but it is to be understood. that such detailed description is not to be taken in a limited sense, since the scope of the invention is best defined by the, appended claims.

'Referring to the drawing: l

Figure 1 is a longitudinal partiallysectional view of a well packer shown in conjunction with a setting tool prior to being anchored to the casing; and

Figure v2 is a longitudinal partially sectional view of the well packer anchored to the casing, shown in conjunction with production tubing.

In the drawing, the well device of the instant invention is illustrated as a production packer A adapted to be set within a well casing B by asettingvtool C secured to the head IU of the packer and to the lower terminus of a tubular string D, by means of which the packer is raised or lowered within the casing. .After the packer has been set in position, as later described, the setting tool and tubular string are removed, and production tubing E is run into the casing from the surface of the well bore until its lower head ll makes sealing'contact with the setting head H3 of th packer.

. The packer is of the retrievable type, and comprises a main body, including a central, tubular portion l2, having the aforementioned setting head l threadedly orotherwise secured to its upper; end. and a guide l3 threadedly or otherwise secured to its lower end. Circumscribing the body is a packing sleeve l4, preferably of rubber, its upper end-interlocking with a packing anchor l5, prevented from moving upwardly by abutting the lower portion of the setting lockring Relative longitudinal movement between the cone l9 and slips 2!! will result in radial movement of the slips either into or out of contact 7 with the casing B.

As the packer is-beinglowered throughthe casing, both the cone and slips are held in inefiective position by sets of shear screws 2!, 22,

23, The shear screws 2 [securing the cone to the main body require a lesser shearing force to disrupt them thanthe screws 22 securing the slips tothe main body. The shear screws 23 attaching the upper ends of the slips to the cone have a higher shear value than the first two mentioned sets of screws.

The packer A is lowered to the desired point within the casing through the agency of the tubular string D and settingtool C,- the latter being suitably disconnectably secured to the packer head ID by the left hand threads 24. The setting tool has a lowerhead 25 carrying aplurality of packing rings 26 for making sealing contact with the inner cylindrical surface 21 of the centralbody portion I2. This head also has an axial bore 28 extending therethrough into communication with the interior of the tubular setting tool portion 29, to permit passage of fluid through the tubing string D as it is being lowered in the bore. However, upon reaching the desired point in the casing, a tripping'ball 30 or the like is allowed to gravitate or is pumped down the tubular string into seating engagement with a tripping ball seat 3| surrounding theaxial bore. After such engagement occurs, the pressure of the fluid can be built up within the tubular string through suitable operation of a pump at the surface, this fluid'leaving the interior of the setting tool through a plurality of lateral ports 32 and entering the cylindrical space 33 between the setting tool head and the packing rings 25. From this space, the fluid under pressure passes through lateral fluid ports 34 extending from the interior of the body into communication with the interior of the packing sleeve l4.

When sufiicient pressure has been built up, the fluid will first engage the packing sleeve It with the walls of the casing and then elongate it in a downward direction to shear the various screws 2|, 22, 23 and slide the cone [9 downwardly along the body to produce radial outward movement of the slips 2!] into gripping engagement with the walls of the casing, due to the cooperable inclined surfaces provided on the cone and slips.

As aforementioned, the force required to shear the screws 2| holding the cone to the body is less than that of the screws 22 holding the slips to the body, and the shear value of the screws 23 initially attaching the slips to the cone is greater than that of the other two sets of screws. For this reason, the shear screws 2| holding the cone to the body will first be ruptured by the force of the fluid and then the shear screws 22' holding the slips to the body, but the connecting screws 23 between the cone and the slips will not be sheared until the cone and slips as a unit have been moved downwardly into engagement with an abutment, in the form of a slidable sleeve 35 initially secured to the main body portion I2 by shear screws 36, and thereby retaining a helical spring 3'! under compression between a flange 38 on the sleeve and the lowerguide [3 of the main body of the packer. Assuming for the present that this abutment 35 is rigidly secured to the body and incapable of sliding movement thereon, the downwardly moving slips 20 will engage it, after which further hydraulic eifort imposed on the cone will shear the interconnecting screws 23 and allow the cone to move downwardly along the inclined faces of the slips and expand them outwardly into engagement with the casing. Thereafter, down wardly directed weight imposed on the packer body through the tubular string D will move the packer downwardly and compress the rubber packing sleeve I4 between its body portion l2 and the casing B, thus providing a leakpronf seal therebetween (as shown in Figure 2).

It is to be understood that the wickers or teeth 20a on the slips are directed downwardly to prevent the packer from moving in that direction by an upward pull on the tubular string D and packer body l0, l2, [3, which action will also release the packing sleeve M from engagement with the casing by again elongating it, an encircling coil spring 39 or other elastic member received within external grooves 40 in the slips will tend to move the slips inwardly away from the sides of the casing.

Upon being set within the casing, the setting tool C is removed from the bore by first turning the tubular string D to the right and unscrewing the setting head [9a from the packer head ii]. The tubular production string E can then be lowered through the casing until its inclined head H engages a companion inclined portion lDb at the upper end of the packer head ID, a sealing ring 4! being carried by the tubing head to ensure that leakage will not occur between the two mating head portions. The subjection of the packed body to the weight of the string E will again compress the packing [4 into sealing contact with both the casing and packer body and also urge the slips more strongly into engagement with the casing through the expansion eifect of the downwardly movable cone l9.

If desired, the lower guide member l3 attached to the packer body can be externally threaded to permit the connection of a tail pipe 42 thereto. If this tail pipe is of sufficient length, its weight will be adequate to maintain the rubber sleeve I4 in packed-oil condition and the slips 20 embedded in the casing wall during the interval between removal of the setting tool C and the running-in of the tubular production string E and its engagement with the packer setting head It]. But if a tail pipe of sufficient weight is not employed, upon removing the setting tool the compressed packing will inherently tend to elongate and move the body portion I2 and cone 19 away from the slips, permitting the encircling coil spring 39 to retract the latter members from the casing, whereupon the packer A would gravitate to the bottom of the hole.

To obviate this possibility, the above described slidable sleeve 35, helical spring 31, and shear screws 36 are employed. The screws 36 have a greater combined shear value than the screws 2|, 22 attaching the cone and slips to the body, but a lesser shear strength than the screws 23 connecting the cone and slips together. Accordingly, during the setting operation, the packing sleeve M will elongate to move the cone l9 and slips 20 downwardly as a unit, after first shearing the screws 2|, 22, until the slips engage the slidable sleeve 35. Further increase of the fluid pressure will urge the slips against this sleeve with a force sufficient to cause failure of the screws 36 securing the sleeve to the body and move it downwardly until the spring 31 is either compressed to its fullest extent, or until the lower end of the sleeve abuts the packer guide 13. Additional increase in the fluid pressure will thereafter shear the screws 23 connecting the cone and slips together and allow the cone to move downwardly with respect to the slips and force them radially outwardly into engagement with the casing.

With the employment of the helical spring 31, the removal of the setting tool does not result in release of the slips since the spring is constantly tending to move the slips and cone toward each other and maintain the former members wedged outwardly into engagement with the casing. This action on the cone is obtained through the intermediary of the guide l3, tubular body portion l2, packing anchor i5 and packing sleeve 14. Although the spring 3'! can be made strongly enough and of sufiicient length to maintain the rubber sleeve M in packed-0H condition with no external load imposed on the packer body, this is not essential so long as it is capable of exerting continued effort to ensure engagement of the slips with the casing and thereby prevent the packer from moving downwardly within the casing after it has been set. Its action will not prevent complete retrieval of the packer or its resetting at a higher elevation by any suitable means that might be run into the hole, such as a tubular string with a square left hand threaded sub on its bottom, or some fishing tool or releasing spear. The coupling of any device of this character to the packer will permit an upward pull to be taken on the packer body and its elevation within the casing or entirely therefrom.

Packers of the type illustrated are particularly adapted for use in multiple zone production. A packer will separate two producing zones communicating with a single bore, production from the lower zone passing upwardly through the packer A and the producing string E connected therewith, and flow from the upper zone passing through the annular space between the casing and the tubular string E.

While the invention has been described with particular reference to a productionpacker, it is to be understood that it is susceptible to other applications within a well bore, as for example, as a liner hanger.

The arrangement employed for setting the packer is both described and claimed in my invention made jointly with Eugene Graham, Jr., Serial No. 269,120, filed April 21, 1939, entitled Production packer and liner hanger, now Patent Number 2,189,701.

I claim:

1. A well packer, including a body adapted for attachment to a tubular string for passage through a well casing, slips for securing said body to said casing, an expander having a downwardly converging outer surface cooperable with companion surfaces on said slips, and a packing member for effecting a seal between said body and casing and adapted to be actuated by fluid under pressure to move said expander downwardly of said slips and effect engagement of the slips with the casing.

2. A well packer as defined in claim 1, said slips having external wickers shaped to prevent substantial downward movement of said body upon embedding of said wickers in the casing.

3. A well packer, including a body adapted for attachment to a tubular string for passage through a well casing, slips for securing said body to said casing, an expander having a downwardly converging outer surface cooperable with companion surfaces on said slips, an extensible packing sleeve secured at its upper end to said body and at its lower end to said expander, said body having a port therethrough for the passage of fluid from the tubular string to said packing sleeve, whereby fluid under pressure can extend said sleeve and move said expander downwardly to effect engagement of said slips with the casing.

4. A well packer including a body adapted for attachment to a tubular string for passage through a well casing, slips for securing said body to said casing, an expander having a downwardly converging outer surface cooperable with companion surfaces on said slips, frangible means for securing said slips and cone to the body in retracted position, and a packing member for effecting a seal between said body and casing and adapted to be actuated by fluid under pressure to disrupt said frangible means and move said expander downwardly of said slips to produce their engagement with the casing,

5. A well packer, including a body adapted for attachment to a tubular string for passage through a well casing, means for securing said body to said casing against substantial movement in a downward direction, means responsive to fluid under pressure for moving said means into engagement with said casing, and means for yieldably maintaining such engagement.

6. A well packer, including a body adapted for attachment to a tubular string for passage through a well casing, slips for securing said body to said casing against substantial movement in a downward direction, an expander cooperable with said slips, hydraulically operable means for producing relative movement between said slips and expander to move the slips outwardly into engagement with said casing, and spring means for urging said expander and slips with respect to each other to maintain such engagement.

7, A well packer, including a body adapted for attachment to a tubular string for passage througha well casing, slips for securing said body to said casing against substantial movement in a downward direction, an expander cooperable with said slips, hydraulically operable means for producing relative movement between said slips and expander to move the slips outwardly into engagement with said casing, and normally ineffective spring means adapted to be rendered effective by relative movement of said expander and slips to tend to move them with respect to each other and maintain the engagement of the slips with the casing.

8. A well packer, including a body adapted for attachment to a tubular string for passage through a well casing, slips for securing aid body to said casing against substantial movement in a downward direction, an expander cooperable with said slips, hydraulically operable means for producing relative movement between said slips and expander to move the slips outwardly into engagement with said casing, a sleeve slidable on said body, a spring between said sleeve and body, means fixedly securing said sleeve to said body to hold said spring in ineffective position, said means being disconnectable to render said spring effective to urge said sleeve against said slips and maintain their engagement with the casing.

9. A well packer, including a body adapted for attachment to a tubular string for passage through a well casing, slips for securing said body to said casing, an expander having a downwardly converging outer surface cooperable with said slips, hydraulically operable means for moving said expander downwardly with respect to said slips to move them downwardly and radially outwardly into engagement with said casing, a sleeve slidable on said body, spring means between said sleeve and body, frangible means normally securing said sleeve to said body to hold said spring means in ineffective position, said frangible means being disrupted by downward movement of said expander and slips to permit said spring means to urge said sleeve against said slips and maintain their engagement with the casing.

10. A well packer, including a body adapted for attachment to a run-in string for passage through a well casing, slips for securing said body to said casing, an expander cooperable with said slips, spring mean for moving said slips and expander longitudinally with respect to each other to hold said slips in engagement with said casing, means normally securing said spring means to said body in ineffective position, and means movable externally along said body for disconnecting said securing means and rendering said spring means effective.

11. A well packer, including a body adapted for attachment to a run-in string for passage through a well casing, slips for securing said body to said casing, an expander cooperable with said slips, spring means for moving said slips and expander means longitudinally with respect to each other to hold said slips in engagement with said casing, means normally retaining said spring means in ineifective position, and means movable externally along said body independently of said spring means for releasing said retaining means and rendering said spring means effective.

12. A well packer, including a body adapted for attachment to a run-in string for passage through a well casing, slips for securing said body to said casing, an expander cooperable with said slips, spring means for moving said slips through, pipe gripping means externally thereof,

and fluid pressure-actuated means for shifting said gripping means including spring means arranged to hold the gripping means lightly in engaged position after release of fluid under pressure against said first named means.

CLARENCE E. BURT. 

